Wash and dry the courgettes and aubergines, and cut into 1cm dice.
Deseed the pepper and cut into fine strips.
Heat the oil in a frying pan and fry the vegetables over a medium heat, stirring regularly, for 2-3 minutes.
Peel and finely dice the garlic and shallot.
Add the shallots and garlic to the vegetables and fry briefly. Season generously with salt and pepper.
Mix the milk, eggs and herbs in a bowl.
Pour the egg mixture over the vegetables, cover, and leave to set for 5 minutes over a medium heat. Shake the pan occasionally to stop the omelette from sticking.
Chop the olives and scatter over the omelette before serving.